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Feb. s, 1929. 7 1,700,996 L. s. BUSHNELL PROCESS OF APPLYING A PROTECTIVE COATING '10 PIPE Filed May 4, 1928 Patented Feb. 1929.

UNITED STATES PATENT QFiFlQE.

LYHAN SHELDON BUSHNELL, OF FKEEPORT, TEXAS, AiSlG-NGR TO .FREEIORT SULPHUR COMPANY, OF FBEEPOBT,

YROCESfl 0F APPLYXNQ A YROTECTIVE COMEIHG "X43 IlPE.

Application filed May 1, 1828. Serial Ho. $25,351.

My invontion relates to a. method of applying scale to pipe and is particularly adapted for use in sulfur mining.

lt is an object of tho invention to place a is corrosion resisting scale upon the pipe used in sulfur mining lifter tho pipe has been laced in position in the Well.

The invontion contemplates tho applying of a scale of sulphates and i i-carbonates of calcium and magnesium and similar salts upon the surface of the pipe, the said scale having the meet of proventing thoaction oi". corrosi e liquids upon the pipe, and also to insulate the Pipcso to pro'vent electrolytic l5 action of the fluid =2 )on the pipe.

In the mining 0 Suit 1' by ho sci-milled Frasoh method, the. mine is drilled do wn to the sulfur stratum and a concentric system of pipes is introduced into the woll for the purpose of forcing the Water down to tho vicinity of the sulfur. This water is callod mine water and is heated tosuch a. touiperiitnrc as to melt the sulfur with which it cox-nos. in. contact and causo it to flow toward the bottom of the Well to tho lower and of the eduction pipe whom it may he. raised to tho Slll'fkltill through tho pressure of tho liquid upon the; sulfur and tho :1. 5211106 of on air lilt which. aerates the sulfur and lands to lift it up wardly to the surlace. ln this syoteni of mining, the subl/orrancan strata in wh h tho sulfur orours is ordinarily charged w h cold water, usually salt laden, having other elements in solution, such as sulfur, which tend to corrode the pipe. Furthermore, the water which occurs in the vicinity of sulfur mines and which must be employed as mine water in the melting of the sulfur is usually impure water having therein various corrosive elements which cannot be economically eliminoted and which tend. to our-rode the appliratus.

My invention has as its broad object llic frotocting of the pipes QllllPlOYi-Kl in tho sulf mining apparatus by scaling thereon :l, coating covering the surface of the pipe and serving to protect the same from irontaot with the water and other flows which tend to corrode the pipe.

Referring to the drawing herewith, l have illustrated thou pfillllillfu'llSll'i isconn ttedup at the surface 0: the ground. The iipes cxtending into the well are indiozited in central vertical. section, and the! appomrus is some what diagrammatically ohm-":1.

Referring to he d rowing, the W6 which is to be. operated is. shown at It has an outer surface pipe 1 which usually is extended down "willy to roloin the walls of the well ir position. The mining apparatus includes 3. hoot d ir- 5 pt: I, iipilliflkl from the walls of the wall having laterally connecting pipe l5 2 f ipur and, said pipchaving a vulvo 1 1 ti on; lo ooiitrol the flow of liquid into the w The uppssr ond of the pipe 5 has thorrin i smiling; box ll which iszidaptod to make a. closure hit-tween tho pipe 5 and the sulfur disohm'go piyc l.

The pipe '2 ll-ll .itw 1min lln: surface to the lowvr will of this well where it. is adapted to project. lilli) lilo moltcii sulfur and to allow the discharge Llior from of the sulfur in this molten moi. 'liso upper ciuil oi tho pipe 7 has Lllr"l1ll'8 5 25 having 22. vaivo 15 thercin "m (totlilol ow pilbi ilgil of the sulfur. l llG army-r oil t? zips}, T has. a smiling i101 12 than yipc "I about the inner pipe 9. which ilul to convey air under pro re (l( .fll-n1ll point spaced some-- What from tho mi" ond oi' lllli sulfur discharge pipo 1'. 'llio air from tho air line hubhles up l rou l in molten sulfur, aerating it and ta lift it. "upwardly to the surface. wlzcro i 15 discharged through tho brooch lino Whei'i tin: minim is llius installozi, the invention coo is in my approval method of depositing scale rayon tho pipes to protect them in the manner previously noted. This is done by pumping into Contact with the pipe surfaces liquid containing limits in solution which are adapted to precipitate out scale upon tho pipes. Sulplnites and iii-carbonates of calcium and magma-iron: are preferably employed for this purpose, although other similar rlonmm; he i ploycd. lron ill-3:1, or 0 :i. c ients, either in solution or in m, only lJU employed, as desired. h rling 1 water has a number of salts inclmlmg sulphates and oarliOIlillffS oi Palciun: and nmgmsium, and it is intended to flliliill you water as Ll vehicle for con voyi 21g 111 mlt' imlo oomzi t with tho. pipe. The proper content of sa obtained by mixing Willi the sea Wulcr ouch further inare orcessury.

o prefcralilymixed withr ii and agitated therein ii sons of 6' ur-nod at the bottozn of the container throi'q 1 an air line 29 connecting with the pipe 30, leading to a source of air under pressure:

A pump is employed to force the treated liquid into contact with the pipe and said pump is connected with the mixing tank B by means of a pipe 18 having therein a valve 23 to regulate the flow of liquid from the tank to the pump. The discharge end of the pump connects with a pipe 14 having branch lines 16 and. 17 with valves therein to control the flow of the salt-ladeti liquid through either of said branch lines. The line it? is conneeted to the pipe 8, previousl noted, and the pipe 16 is connected with t e pipe 6, as will be seen in the drawing.

The usual steps in the scaling of the pipes eonsist in first applyin the scale to the outside of the air line 9 an the inside of the pipe 7. This is accomplished by forcing hot water or steam at the proper temperature downwardly through the pipes 9 and 5 This hot Water Will serve to heat liquid within the space 19 between the two healed surfaces, the pipes 9 and 7. With the hot water thus circu lating, a salt-laden liquid is pumped through the pipe 17 and into the line 8, leading to the space 19, and liquid thus flnwlng into the heated space will become heated in roman-t with the pipe. It planned to pump the cold fortified sea water through the pipe 7 at a re ,id and radually decreasing velocity. The salt-laden iquid will become heated to a temerature at which the salts mntained in the iquid will be deposited upon theputer side of the pipe 9 and the inner side of the pipe 7, the Water being pumped rapidly down will carry the same to a point near the bottom of the Well before. the salt is precipitated out. This velocity will he gradually decreased so that the scale will be gradually deposited at points farther up until finally the whole interior of the pipe 7 and the exterior oi the pipe 9 will he covered with scale of the proper thickness heating liquid in The pipe 6 may he raised to any 1 esired temperature by means of a steam line which adapted to discharge steam through a nipple 27 into the )ipe 6, said nipple 27 being welded within tinside of the pipe, as indicated in the (l!l1\\lll W'hen the pipes 9 and 7 have been; vsealed within the chamber 19, the circulation will he stopped and hot water will lie circulahwl into the space 19 within the ipe 7'. and the cold salt-laden sea water will is pumped inwardly through the pipes 6 and 16, the valve in the pipe 17 being closed: This waler will he partially heated through steam from pipe 27 and partly fromrontact with the heated pipe 7. The pipe 5 may he thus seal d on its inside and the outer side of pipe 7 s ill siinilurlv l e scaled. It desired in this sealing: pro es to ump the sea Water at a slow rate at ill t and gradually increase the velocity of (he salt-laden liquidrso that the upper part of mousse to protect them from corrosive liquids employed in the mining or" the sulfur, the usual impure liquid obtained and used or sulfur mining will have no effect upon the pipes through which the water is circulated, the said pipe being thus thoroughly protected against the attacks of acids or other corrosive elements upon the pipe.

In the usual process of sulfur mining. bleed wells are usually drilled io-allow the outlet of Water from the sulfur stratum so that the hot Water being pumped into the well may ireulate into the stratum to maintain it at the proper temperature The water discharged from these bleed wells usually hot and but for the corrosive action of the chemical elements unstained in the water, this water could be reused in mining I here shown a pipe :25 hauling from a bleed Well through which the fm'ination water may be discharged into a rat I) and there agitated through an air line 28 for treatn'ieut, as desiredi It may then be pumped into the well for transferring the heat to the sul to r stratum and as it is passed through the pipe 6 it may be furtherhcated through the use of "the steam Max:201 as previously noted. and it will be ohvious that economy in the heating of this wat r will be accomplished in this manner.

By employing the formation water from the line 25, several important advantages are ob tained. It is possible to use water which would otherwise he Wasted. thus avoidin r the necessity oi ilrziiwing on the supply of ooh We ter, and furthermore, the water thus retained is already heated. to a fairly high temperatue and a lim ted amount oi? heat is necessary to raise this liquid to the proper temperature for fusing the sulfulx It to he uniilerslood, of course lhiit the advantage of sealing the pipe is not entirely in the fact that the OlZlGl'ZllOl is enabled to use the hot Water from the mine. Much of the water obtained in the vicinity of sulphur mines is more or contaminated with corrosive elements which cause a rapid deterioration. in the pipes; lVhon the pipe has been thus scaled, it is not attacked by these corrosive liquids Also the scale forms unelcctrical insulaiim; coating which prevent: electrolysis which ordinarily tends to cause the rapid disintegration of the metal pipes.

This process w hereby the sealing liquid may be heated in direct contact with the pipe where it may he precipitated from solution and deposit directly upon the pipe enables the operator to deposit upon the ipe a uniform scale of desired thickness wit out difiiculty.

Having thus described my invention, what I claim as new is:

1. A method of scaling pipes including installing said pipes in concentric relation spaced apart to form fluid conducting passages between adjacent pipes, discharging heated liquid into the pipes on each side of one of said passages, then circulating a saltladen liquid into the passage to be sealed and allowing said salts to deposit upon the adjacent pipes as the temperature of said saltladen liquid is raised.

2. A method 0 forming a layer of scale upon a series of concentric pipes in wells, having fluid passages between them eon'iprising heating the walls of the passage to be scaled, and then forcing through said pal-sage a liquid laden with salts, and allowing said salts to precipitate upon the walls of said passage as the temperature of said liquid is raised.

3. A method of forming a layer otscale upon a series of concentric pipes in wells, having fluid passages between them, comprising heating the walls of the passage to be scaled, and then forcing through said passage a liquid laden with salts, and allowing said salts to precipitate upon the walls of said passage as the temperature of said liquid is raised, and varying the rate of flow oi' said liquid to allow the deposit of scale at different levels in said passage.

4. A method of ft'illnillg a layer of scale upon a series of concentric pipes in wells, having fluid passages between them, coinpris ing heating the calls of the passage to be scaled, and then forcing through said passage a cold liquid laden with sulphates and carbonates of calcium and magnesium, and allowing said sulphates and carbonates to precipitate upon the Walls of said passage as the temperature of the liquid is raised.

5. A method of forming a layer of scale upon concentric pi pcs in wells having fluid passages between them comprising heating the walls of the passage to be scaled by pumping heated fluid through a passage adjacent thereto, forcing into the passage to be sealed a cold liquid laden with salts to he precipitated, and varying the rate of flow of said liquid to deposit the scale at various levels.

6. A method of depositing scale upon pipes in sulphur mining con'iprising heating A walls of the pipe to be scaled, circulating into contact with the heated pipe a cold fortified salt water, and gradually heating said water in contact with said pipe to cause said salt to precipitate upon said pipe.

in testimony whereof l hereunto allix my signature this 24th day of April A. l). 1925.

LY MAN SELDON B USHN ELL. 

